Validation rules

UBL-SR-09

The seller name (BT-27) appears more than once — the supplier party may carry only one PartyLegalEntity/RegistrationName.

Rule: UBL-SR-09 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-27 — Seller name
Field in your JSON: invoice.seller.name
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Only reachable when validating your own XML — normbill-generated documents cannot trigger it

The serializer writes invoice.seller.name as exactly one RegistrationName.

How to fix it

Keep a single cac:PartyLegalEntity/cbc:RegistrationName under cac:AccountingSupplierParty.

UBL-SR-09 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil der Verkäufername (BT-27) mehrfach vorkommt — die Verkäuferpartei darf nur einen PartyLegalEntity/RegistrationName tragen.

So beheben Sie den Fehler

Behalten Sie genau einen cac:PartyLegalEntity/cbc:RegistrationName unter cac:AccountingSupplierParty.

Official sources

Every 422 from the API lists the rule id, the path in your request JSON, a plain-language message and a suggested fix — see the docs overview for the report format.

Or try it live: drop any XRechnung XML on the free validator — same KoSIT-backed report, no account.